darlina



{No Model.)

2 Sheets Sneet 1.

J. D. DARLING.

METHOD OF AND APPARATUS FOR-MANUFACTURING SULFURIG ACID AND BY-PRODUGTS.

Patented June 25 1895.

INVENTOR Y qNo Model.) I 2 Sheets-Sheet 2.

J. D. DARLING. METHOD OF AND APPARATUS FOR MANUFACTURING SULFURIU ACID AND BY-PRODUGTS- V I r 4 Patented June 25; 1895.

e; ce. i J x UNITED "STATE PATENT t niest JAMES D. DARLING, OF PHILADELPHIA, PENNSYLV XNIA, ASSIGNOR TO HARRISON BROTHERS d: 00., F SAME PLACE.

METHO D (lF AND APPARATUS FOR MANU FAClTURING SULFURlC AClD AND BYJRODUCTSr SPECIFICATION formingpart of Letters latent No. 541,597, dated June 25, 1895. Application filed January 8, 1895- Serial No. 584,197. (No model.)

To all whom it may concern.-

Be it known that 1, JAMES D. DARLING, a resident of the city of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in the Mannfacture of Sulfuric Acid and By-Products and in Apparatus Adapted to such Manufacture, whereof the following is a specification, reference being had to the accompanying drawwas. i

M y invention is addressed to the economical manufacture of sulphuric acid, by so producing one of the necessary reagents for the general process as to incidentally develop a by-produet of high commercial value. I also organize the required apparatus in such manner as tofacilitatc continuous and uniform working.v

The usual method of supplying the nitrogen compounds required in the commercial manufacture of sulphuric acid is to decompose nitrate of soda, or nitrate ot' potash, by'heating it with sulphuric acid to liberate the nitric acid gas, (N-HO li which is then passed, as such, into the Glovertowcr and there decom posednucl utilizedin' the necessary reaction. The by-product of this portion of the process is an acid sulphateof soda or potash, (usually called niter cake) having little commercial value.

I have found that by electrolytically decomposing nitrate of soda or nitrate of potash, the liberated gases (NO,+O) may, without conversion into nitric acid, or further modification, be directly conveyed to the Glover tower and serve the necessary put pose for the development of sulphuric acid, while at the same time the by-product of such electrolytic action can be obtained in a condition which gives ita high commercial value.

I will now proceed to describe the process in connection with a typical apparatus, some of whose features are of themselves new and the subject of my invention.

In the accompanying drawings, Figure 1 in dicates, without,- detail, certain general fe'atures of asulphuric-aciti plant, shown in side elevation. Fig. 2 is a vertical ceutral'sectiou through one of the vessels in which the elec tro'lyticaction, characteristic of my process,-

with the upright stack or dustchainber, A, i

which in turn communicates by a transverse 6o flue, a, with a Glover tower, A Withinthe due, a, I place the vessel in which the electrolytic decomposition of the nitrate is to be efiected, thus utilizing the heat of the gases from the pyrites kilns for maintaining, in a fused condition, the nitrate which is tc'be utilized. I prefer to employ aplurality of decomposing vessels, in order that the process may be practically a continuous one, and in the gen. 7o

eral view have indicated two. Any number, hbwever, may be used which the circumstances ofthe case render desirable. These vessels, B and B, communicate by means of pipes, b, b, respectively, with a common duct,

(3, leading to the flue, a, and thus discharging into the interior'of the Glover tower, A}; Communication between the several vessels and the duct, 0, is controlled by means of valves, as c, c. A portioh of the pipes, b, 1 8c may be of glass, as indicated at f, fflto permit inspection of the interior at those points.

Refcrringnow to the detail views shown in Figs. 2 and 3, a description will be given of one of the decomposing vessels as typical of therest. ,,j I

The vessel, B, is preferably made of cast iron and is substantially rectangular in form,

having an opening at one end o fth'e bottom for a discharge pipe, Ii, controlled by acoclr, 0

h. A removable cover, D, is secured upon the top of the vessel, being, however, lllSlilfilJfith.

electrically therefrom by a layer of refractory non-conducting material, indicated at d. .A

or plate, K, of metal, having less electrical 'rewe series of cast iron plates, E, depend down- 5 of liberated gasses, leads 'out from the top.

7 The vessel, B, is electrically connected by means of the wire, J, with the negative pole [O of any suitable source of electricity, while the plates, E, are similarly connected by means of the wire, J',-with the positive pole thereof. The vessel itself thus serves as the negative electrode, and the plates, E, as the 15 positive electrode for the electrolytic action upon the contents.

In practice the vessel is filled with nitrate of soda to the level indicated by the dotted lines, L. Assuming that the pyrites kilns are no in operation, anddischarging the hot sulphnrous acid gas, the latter passes through the flue, a, into the dust stack, A, where it deposits its dust, and thence passes into the Glover tower, 41. The nitrate which is mainz5 tained in a fused condition within the vessel,

B, is decomposed by the passage of the electric current, giving cit nitrogen per-oxide and oxygen (NO -O). These gases-pass through the pipe,'b, into the duct, 0, and thence are 3o discharged, as such, into the Glover"tower,A

without conversioninto nitricacid. Thenitrogen per-oxide there acts directly in the general reaction necessary for the production of sulphuric acid, the process in this respect 35 diifcring as a whole from those in which acid fumes (NllO are supplied to the Glover tower, since in this latter case the decomposition of the nitric acid and the development of nitrogen per-oxide must first be eifected, 40 while by my process the necessary nitrogen peroxide is developed and introduced in the first instance.

The electrolytic decomposition is continuous withinthe vessel, 13, as long as nitrogen 5 peroxide is given oil. The duration of this action may be ascertained by observing the color of the gas in the glass portion,f, of=the another vessel, such as B, similarly constructed, and the process repeated. In the meanwhile the residuum within the vessel, B, (consisting mainly of sodium monoxidei'if nitrate of soda has been used, or the corresponding salt in other cases,) is run ofi through the outlet pipe, H, and a fresh charge of nitrate of soda is supplied, ready to be utilized as soon asthe action in the vessel, B, is complete.

The monoxide of sodium, or similar residuum from the vessels, is dissolved in a limited quantity of water to form a hydrate,and the undecomposed nitrates, if any exist, can readily be: separated therefrom, leaving a pure caustic solution, which may be concentrated, by boiling, into caustic soda, in the usual manner.

Having thus described claimr v 1. The hereinbefore described process for the manufacture of sulphuricacidand byproducts, which consists in electrolytically my invention, l

decomposing a fused nitrate, directly conducting the disengaged gases, without further conversion, to the Glover tower, and recover ing the basic residuum of the electrolytic action, substantially as set forth.

2. In asulphuric acid plant comprising pyrites kilns, a Glover tower and an intermediate fiue, the combination with said fine of a closed vessel forming a negative electrode, a positive electrode situated within said vessel, a discharge pipe leading from said vessel to ,a point of communication with said tower,

and a source of electricity in circuit with said electrodes, substantially as set forth-.

JAMES D. DARLING.

\Jitnesses:

HERMAN G. Soasncnn, S DNEYS. EMERY. 

